The present invention relates to improvements in apparatus for supporting and positioning photographic material in copying machines. More particularly, the invention relates to improvements in apparatus for supporting and positioning discrete photographic roll films, a series of photographic roll films which are spliced to each other end-to-end, or sections of discrete photographic roll films during exposure of selected or successive film frames for the purpose of making reproductions on photographic paper or the like. Still more particularly, the invention relates to improvements in apparatus for supporting and positioning perforated photographic roll films in a photographic copying machine wherein selected film frames register with a window and are illuminated by light during reproduction of their images onto a layer of photosensitive material which coats one side of a strip of printing paper or the like.
A photographic copying machine must be provided with an apparatus or device for properly positioning selected or successive film frames in register with the light-transmitting window and for maintaining such frames in a predetermined plane. This insures the making of satisfactory prints as regards the contrast and/or other characteristics of reproduced images. The just mentioned apparatus must be further capable of rapidly locating the film in an optimum position for engagement with automatic advancing means and for holding the film frame which registers with the window in an optimum position, as considered longitudinally as well as transversely of the film. To this end, many types of roll films are provided with perforations in the form of holes or notches, preferably at least one for each film frame. Such perforations can also serve to facilitate the transport and/or positioning of film frames in a still camera or motion picture camera, i.e., before the film is developed and thereupon introduced into a copying machine.
Certain film positioning and supporting apparatus for use in high-speed copying machines already comprise detector means for scanning the perforations and for regulating the operation of automatic film advancing means. Suitable detector means is disclosed in commonly owned U.S. Pat. No. 3,874,791 granted Apr. 1, l975 to which reference may be had, if necessary. However, it is often desirable to insert and advance a section or a full length of photographic roll film by hand, for example, when the customer returns a section of film for the making of more satisfactory or additional prints. Such sections (e.g., sets of four film frames) are normally too short to be properly transported by automatic advancing means which is used primarily for the transport of webs consisting of a large number of spliced-together photographic roll films immediately after the films issue from a developing machine. Furthermore, even if the sections are not too short for automatic transport, it would be more time-consuming to properly thread such sections into the automatic advancing means than to position successive film frames of a single section (or a small number of sections) by hand. Still further, certain types of photographic film are bonded or otherwise connected to data-carrying strips of paper or the like; such films have perforations along the "wrong" marginal portions, i.e., not along those marginal portions which are formed with perforations in a roll film without a data carrying strip.